PRECIPITATION ANOMALIES OVER SOUTH AMERICA IN THE
SUMMER SEASONIN SCENARIOS OF CLIMATE CHANGE
Iracema Fonseca de Albuquerque Cavalcanti
CENTRO DE PREVISÃO DE TEMPO E ESTUDOS CLIMÁTICOS
INSTITUTO NACIONAL DE PESQUISAS ESPACIAIS
COLD AIR OUTBREAKS OVER SOUTHEASTERN SOUTH AMERICA IN THE
WINTER SEASONIN SCENARIOS OF CLIMATE CHANGE
Gabriela Müller Kelen Andrade Iracema FA Cavalcanti
ANOMALOUS PRECIPITATION OVER SOUTH AMERICA
• NATURAL CLIMATE VARIABILITY
• ENSO CONDITIONS (EL NINO / LA NINA)
• TELECONNECTIONS
• INTRASEASONAL OSCILLATION
• BEHAVIOUR OF SYNOPTIC SYSTEMS
• BLOCKING SITUATIONS
• ETC
DROUGHT IN 2005
DROUGHT IN 2000/2001
DROUGHT IN 1997/1998
THE QUESTION IS:WILL THE ANOMALIES CHANGE
IN SCENARIOS OF CLIMATE CHANGE OVER SOUTH AMERICA?
HOW THE INTENSITY OF NATURAL VARIABILITY CAN CHANGE IN THE
FUTURE?
MODELS
CPTEC/COLA AGCM
DJF PRECIPITATIONCMAP/CAMS
Extreme wet years composite Extreme dry years composite
SOUTHEASTERN BRAZIL (50W-40W; 15-25S)
Extreme wet years composite Extreme dry years composite
IPCC-4 MODEL SIMULATIONS
20 CENTURYSRES A2
PRE-INDUSTRIAL
1% CO2 INCREASE
MODELS
HADLEY HADCM3
GFDL
HADGEN
MRI
ECHAM
CANADIAN
Increase from CO2= 286.05 ppm at 1% /year rate to doubling, then constant to year 280. Other gases cte from 1860
1% CO2 EXPERIMENT
20TH CENTURY EXPERIMENT
Considers all anthropogenic forcings during the period of 1860 to 2000 (140 years)
EXPERIMENTS
SRES A2High degree of global economic development (means high concentration of greenhouse gases)
(2000-2100)
Forcings agents representative of 1860 conditions constant. Include all greenhouses gases (280 years)
PRE-INDUSTRIAL EXPERIMENT
PERIODS OF ANALYSIS
• LAST 51 YEARS FROM EACH SIMULATION
• DJF (S.H. SUMMER)
• 20 CENTURY : 1949-1999
• SRES A2: 2048- 2098 OR 2049-2099
20 CENTURY
DJF 1979/1980 TO 1999/2000
GFDL MRI HADCM3
OBSERVED
PRECIPITATION
MODELS SIMULATIONS
HADGEN ECHAM
OBSERVED
PRECIPITATION
CANADIAN
MODELS SIMULATIONS
Difference between two periods in the pre-industrial experiment (year 71 to 280)- (year 11 to 70).
The changes are very small, consistent with the absence of anthropogenic forcings.
PRE-INDUSTRIAL EXPERIMENT GFDL
The impact on precipitation is seen in the region of
South Atlantic Convergence Zone
and Southeastern South America considering the two experiments.
DIFFERENCES BETWEEN 1%CO2 AND PRE-INDUSTRIAL EXPERIMENT GFDL
DIFFERENCES BETWEEN 1%CO2 AND 20th century EXPERIMENTS GFDL
ANNUAL GFDL
GFDL (USA) DIFFERENCES (FUTURE -20TH CENTURY)
DJF1%CO2 SRES A2
HADCM3 (UK)
DIFFERENCES (FUTURE -20TH CENTURY)
1%CO2 SRES A2DJF
GFDL20 CENTURY LAST PERIOD 1% CO2 INCREASE
250 hPa
850 hPa
Difference between SRES A2 and 20th century wind flow
HADLEY.
EXTREME MONTHLY PRECIPITATION ANOMALIES
DJF
• Average of precipitation anomalies over several areas of South America
• 5 extreme years (+ and -)
• 20th century and SRES A2
• Hadley and GFDL
WAmazonia
E
Amazonia
N La Plata
S La Plata
AREAS
AREAS
SE
NE
GFDL
AMAZONIA
WESTERN SECTOR
20th century A2 ANOMALIES RELATED TO THE CLIMATOLOGY OF 20TH CENTURY
PRECIPITATION ANOMALIES
EASTERN SECTOR
GFDL
PRECIPITATION ANOMALIES (AMAZONIA) GFDL
LA PLATA NORTHERN SECTOR
LA PLATA SOUTHERN SECTOR
GFDL
PRECIPITATION ANOMALIES LA PLATA SOUTHERN SECTORGFDL
NORTHEAST BRAZILGFDL
PRECIPITATION ANOMALIES NORTHEAST BRAZIL
SOUTHEAST (50W-40W; 15S-25S)
PRECIPITATION ANOMALIES SOUTHEAST BRAZIL
HADLEY
HADLEY
AMAZONIA WESTERN SECTOR
EASTERN SECTOR
20th century A2 ANOMALIES
NORTHEAST BRAZIL
LA PLATA NORTHERN SECTOR
LA PLATA SOUTHERN SECTOR
SOUTHEAST Brazil
HADLEY
20th century
SRES A2
PRECIPITATION ANOMALY CORRELATIONS AREA 15S-25S; 40W-50W (SOUTHEAST) GFDL
GFDL
HADCM3
HADCM3
EXTREME PRECIPITATION ANOMALIES SOUTHEAST (50W-40W; 15S-25S) 20th century
GFDL HADCM3
GFDL HADCM3
NEGATIVE
ANOMALIES
POSITIVE ANOMALIES
EXTREME PRECIPITATION ANOMALIES SOUTHEAST
(50W-40W; 15S-25S) SRES A2
GFDL HADCM3
COLD AIR OUTBREAKS OVER SOUTH AMERICA
• CNPq colaboration project Argentina, Uruguay, Brazil.
• Objective: Identify frequency and intensity of extreme cold air outbreaks in the present climate and in the future.
• Will the global warming affect the frequency and intensity of the cold air outbreaks?
TEMPERATURE CHANGES (annual)
GFDL
1% CO2 increase
– preindustrial
1% CO2 increase – 20 century
Frequency of cold air over Brazil, Argentina and Uruguay
• Daily data at (925hPa), 850 hPa
• SLP, meridional wind and Temperature
• Average over areas
• 52W-57W; 23S-28S (Brazil)
• 52W-57W; 28S-33S (Uruguay)
• 65-60W; 33-38S (Argentina)
criterium
• Temperature interval (0-2.5c , < 0c)
• Reduction of temperature (5-8c; 8-10c; >10c)
• Increase of SLP and southerly flow at 850hPa
ARGENTINA STATIONS
0
2
4
6
8
10
12
14
16
18
1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990
frec NCEP
frec OBS
OBS: TEMP. AT 2m
Reanalysis: 850hPa
TEMP. 850 hPa 0-2.50 c
1960-1990
FUTURE
65-60W
33-38S
ARGENTINA - Categoria 0 - 2,5
0123456789
10111213141516171819202122232425
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
NCEPGFDLHADDiário
ARGENTINA - Categoria 0 - 2,5
0123456789
10111213141516171819202122232425
20
80
20
81
20
82
20
83
20
84
20
85
20
86
20
87
20
88
20
89
20
90
20
91
20
92
20
93
20
94
20
95
20
96
20
97
20
98
20
99
21
00
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
HADDiárioGFDLF
Argentina
ARGENTINA - Categoria < 0
0123456789
10111213141516171819202122232425
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
NCEPGFDLHADDiário
TEMP. 850 hPa < 0 c
1960-1990
65-60W33-38S
FUTURE
ARGENTINA - Categoria < 0
0123456789
10111213141516171819202122232425
20
80
20
81
20
82
20
83
20
84
20
85
20
86
20
87
20
88
20
89
20
90
20
91
20
92
20
93
20
94
20
95
20
96
20
97
20
98
20
99
21
00
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
HADDiário
GFDLF
Argentina
FUTURE
1960-1990
TEMP. 850 hPa
0-2.50 c
52W-57W
23S-28S
BRASIL - Categoria 0 - 2,5
0
1
2
3
4
5
6
7
8
9
10
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
NCEPGFDLHADDiário
BRASIL - Categoria 0 - 2,5
0
1
2
3
4
5
6
7
8
9
10
20
80
20
81
20
82
20
83
20
84
20
85
20
86
20
87
20
88
20
89
20
90
20
91
20
92
20
93
20
94
20
95
20
96
20
97
20
98
20
99
21
00
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
HADDiário
GFDLF
Brazil
FUTURE
1960-1990
Temp. 850 hPa
<00 c
52W-57W 23S-28S
BRASIL - Categoria < 0
0
1
2
3
4
5
6
7
8
9
10
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
NCEPGFDLHADDiário
BRASIL - Categoria 0 - 2,5
0
1
2
3
4
5
6
7
8
9
10
20
80
20
81
20
82
20
83
20
84
20
85
20
86
20
87
20
88
20
89
20
90
20
91
20
92
20
93
20
94
20
95
20
96
20
97
20
98
20
99
21
00
Anos
Nú
me
ro d
e O
co
rrê
nc
ias
HADDiário
GFDLF
Brazil
Next criterium
• Calculate anomalies and analyze the extremes in each area.
• Use SLP and meridional wind to get cases associated with frontal systems.
CONCLUSION
COMMON FEATURES IN THE MODELS
• INCREASE OF PRECIPITATION OVER NORTHWESTERN AND SOUTH/ SOUTHEASTERN SOUTH AMERICA.
• REDUCTION OF PRECIPITATION OVER SOUTHWESTERN SOUTH AMERICA.
• THERE IS AGREEMENT IN CHARACTERISTICS ASSOCIATED WITH EL NINO INFLUENCE IN SOME REGIONS
REGIONS WITH DIFERENT RESULTS IN DIFERENT MODELS
• SUGGEST UNCERTAINTY IN CHARACTERIZING THE FUTURE CLIMATE IN THESE REGIONS.
• AND • THE NEED TO ANALYSE RESULTS OF
OTHER MODELS.
• MULTI-MODEL ENSEMBLE
• Extreme monthly anomalous precipitation intensifies in some regions
• Dipole patterns are reproduced in 20th century and future climate scenario
• Extremes are connected in some areas
Frequency of cold air cases
• Number of cold air outbreaks are better simulated by Hadley model (20th century) in two areas of South America.
• Frequency reduces in SRES A2 scenario
• (still analysing the intensity)
WORK IN PROGRESS
• IDENTIFICATION OF MECHANISMS ASSOCIATED WITH THE CHANGES.
• ANALYSIS OF MODEL PATTERNS ASSOCIATED WITH THE COLD AIR OUTBREAKS
• ANALYSIS OF DAILY PRECIPITATION AND TEMPERATURE DATA TO IDENTIFY EXTREMES
• ANALYSIS OF OTHER IPCC MODELS
ACKNOWLEDGEMENTS
To CNPq for research supportTo CNPq/Prosul project
To international modeling groups for providing their data for analysis, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) for collecting and archiving the model data, the JSC/CLIVAR Working Group on Coupled Modelling (WGCM) and their Coupled Model Intercomparison Project (CMIP) and Climate Simulation Panel for organizing the model data analysis activity, and the IPCC WG1 TSU for technical support. The IPCC Data Archive at Lawrence Livermore National Laboratory is supported by the Office of Science, U.S. Department of Energy.
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